What you need to know about modifying a Nissan R35 GT-R | Articles

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Meet Our Expert:
Mike Mahaffey
President, main tuner, AAM Competition
aamcompetition.com

The GT-R is an impressive car. It can run a high-10-second quarter-mile with just a midpipe, downpipe and some tuning. However, to reliably and consistently gain more power, you would want to consider a couple of other upgrades such as a larger intake kit and larger injectors so you do not experience injector lock.

Just so you have a reference point, the factory turbochargers on the GT-R are capable of supporting up to about 580 to 600 wheel horsepower. To reach higher power levels, larger turbochargers are required as the factory turbochargers can literally supply no more air to the engine.

There are several milestones when upgrading the GT-R with factory turbochargers. We call these ”milestones” because no matter what else you do to the GT-R, it will not make any additional power:

• Maximum power without recalibrating the computer: 460-480 whp, depending on the year.
• Maximum power without upgrading the intake: 540-550 whp.
• Maximum power without upgrading the injectors: 540-550 whp.
• Maximum power without upgrading the waste gate actuators: 580-600 whp.
• Maximum power without upgrading the rear exhaust: 560-590 whp.

I like to explain these figures because people often read information on the internet and it can get confusing. For example, although you can make 540 to 550 whp on the dyno with factory injectors, you could not run that power level on the street. When you run a car on the dyno, the load is not as great and the air is not as dense, especially during cooler parts of the year. Plus, the dyno run is just for a short duration. 

On the road or track, an engine takes longer to accelerate, especially in taller gears. When a turbocharged vehicle takes longer to accelerate, more torque is generated as the turbochargers have more time to force air into the engine. 

This additional torque also requires additional fuel to meet the new power output. While the factory injectors might have supplied enough fuel on the dyno to momentarily meet your engine’s fuel requirement, on the street your GT-R would need more fuel. The factory injectors are working at very close to 100 percent duty cycle–their maximum capacity–on the dyno at the 540 whp level. The stock injectors do not have the…